Service Workers Working Group Charter

The mission of the Service Workers Working Group is to enable Web applications to take advantage of persistent background processing, including hooks to enable bootstrapping of web applications while offline.

Join the Service Workers Working Group.

Start date 27 January 2020
End date 30 April 2021
Charter extension See Change History.
  • Jake Archibald, Google
  • Matt Falkenhagen, Google
Team Contacts Yves Lafon (0.1 FTE)
Meeting Schedule Teleconferences: Teleconferences will be held approximately monthly.
Face-to-face: The Working Group will meet during the W3C's annual Technical Plenary week; additional face-to-face meetings will be scheduled by consent of the participants, 1 or 2 times per year.


Web Applications traditionally assume that the network is reachable, which is not always the case. The Working Group will specify event-driven services between the network layer and the application, allowing it to handle network requests gracefully even while offline.

Success Criteria

In order to advance to Proposed Recommendation, each specification is expected to have at least two independent implementations of each feature defined in the specification.

Each specification should contain a section detailing any known security or privacy implications for implementers, Web authors, and end users.

Each specification should have an associated testing plan developed in parallel, and complete by the time the specification reaches Candidate Recommendation; by Recommendation, there should be test suite for each deliverable, sufficiently broad to demonstrate interoperability.

Each specification should have implementation reports showing adoption, fostering the ready availability of multiple, independent, interoperable implementations, including in browsers, authoring, and validation tools, and usage on the Web.

If a critical mass of key stakeholders and implementers of this technology do not join the group, its charter should be re-examined by the W3C.


More detailed milestones and updated publication schedules are available from the Working Group home page.

Draft state indicates the state of the deliverable at the time of the charter approval. Expected completion indicates when the deliverable is projected to become a Recommendation, or otherwise reach a stable state.

Normative Specifications

The Service Workers Working Group will deliver the following W3C normative specifications:

Service Workers 1
Latest publication: 13 August 2019
Reference Draft:
associated Call for Exclusion on 13 May 2014 ended on 05 October 2014
Produced under Working Group Charter:

This specification defines an API to enable applications to take advantage of persistent background processing.

Draft state: Working Draft

Expected completion: [Q1 2020]

Service Workers
Editors' Draft:

This specification defines an API to enable applications to take advantage of persistent background processing.

Draft state: Working Draft

Expected completion: [Q4 2020]

The Working group may produce multiple versions of each deliverable, reflecting developments in how much of the relevant technology is interoperably implemented.

The working group intends to use a parallel specification-editing and -testing approach, where all normative specification changes are generally expected to have a corresponding test change, either in the form of new tests or modifications to existing tests, or must include the rationale for why test updates are not required for the proposed update.

The participants of the current Working Group are looking forward to moving this work to an "Evergreen standard" model as is being discussed for Process 2020.

Other Deliverables

The Service Workers Working Group will decide the next steps for the following WICG specification:

Background Fetch

An API to handle large uploads/downloads in the background with user visibility.

Draft state: Adopted specification from WICG

Next steps for this document may include promotion to Working Group deliverable (with agreed changes), or deprecation.

The following specifications are in scope for discussion and incubation within the Working Group, but formal publication would require a new charter to get consensus and commitments:

Web Background Synchronisation

This specification defines an API that uses Service Workers to permit both one-off and periodic synchronisation of data, for applications that use non-local data storage.

Draft state: Adopted specification from WICG

Web Periodic Background Synchronisation

This specification describes a method that enables web applications to periodically synchronize data and content in the background.

Draft state: Adopted specification from WICG

Next steps for those documents may include promotion to Working Group deliverables (via a new charter), or deprecation.

Other non-normative documents may be created such as:

  • Use case and requirement documents;
  • Test suite and implementation report for the specification;
  • Primer or Best Practice documents to support web developers when designing applications.


  • January 2020: Service Workers 1 Candidate Recommendation
  • January 2020: FPWD for Service Workers
  • April 2020: Service Workers 1 Recommendation
  • May 2020: Proposal for rechartering or closing the Working Group

Success Criteria

In order to advance to Proposed Recommendation, each specification is expected to have at least two independent implementations of each of feature defined in the specification.

Each specification should contain a section detailing all known security and privacy implications for implementers, Web authors, and end users.

There should be testing plans for each specification, starting from the earliest drafts.

Each specification of technologies that directly impact user experience should contain a section on accessibility that describes the benefits and impacts, including ways specification features can be used to address them, and recommendations for maximising accessibility in implementations.

To promote interoperability, all changes made to specifications should have tests.


For all specifications, this Working Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG. Invitation for review must be issued during each major standards-track document transition, including FPWD and CR, and should be issued when major changes occur in a specification.

Additional technical coordination with the following Groups will be made, per the W3C Process Document:

W3C Groups

Web Applications Working Group
This group enables improved client-side application development on the Web, including application programming interfaces (APIs) for client-side development.
Web Performance Working Group
This group provides methods to measure and improve aspects of application performance of user agent features and APIs.
Web Application Security Working Group
This group develops security and policy mechanisms to improve the security of Web Applications, and enable secure cross-origin communication.

External Organizations

ECMAScript Standards Body


To be successful, this Working Group is expected to have 6 or more active participants for its duration, including representatives from the key implementors of this specification, and active Editors and Test Leads for each specification. The Chairs, specification Editors, and Test Leads are expected to contribute half of a working day per week towards the Working Group. There is no minimum requirement for other Participants.

The group encourages questions, comments and issues on its public mailing lists and document repositories, as described in Communication.

The group also welcomes non-Members to contribute technical submissions for consideration upon their agreement to the terms of the W3C Patent Policy.

Participants in the group are required (by the W3C Process) to follow the W3C Code of Ethics and Professional Conduct.


Technical discussions for this Working Group are conducted in public: the meeting minutes from teleconference and face-to-face meetings will be archived for public review, and technical discussions and issue tracking will be conducted in a manner that can be both read and written to by the general public. Working Drafts and Editor's Drafts of specifications will be developed on a public repository and may permit direct public contribution requests. The meetings themselves are not open to public participation, however.

Information about the group (including details about deliverables, issues, actions, status, participants, and meetings) will be available from the Service Worker Working Group home page.

Most Service Worker Working Group teleconferences will focus on discussion of particular specifications, and will be conducted on an as-needed basis.

This group primarily conducts its technical work on GitHub issues. The public is invited to review, discuss and contribute to this work.

The group may use a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and members of the group, for member-only discussions in special cases when a participant requests such a discussion.

Decision Policy

This group will seek to make decisions through consensus and due process, per the W3C Process Document (section 3.3). Typically, an editor or other participant makes an initial proposal, which is then refined in discussion with members of the group and other reviewers, and consensus emerges with little formal voting being required.

However, if a decision is necessary for timely progress and consensus is not achieved after careful consideration of the range of views presented, the Chairs may call for a group vote and record a decision along with any objections.

To afford asynchronous decisions and organizational deliberation, any resolution (including publication decisions) taken in a face-to-face meeting or teleconference will be considered provisional. A call for consensus (CfC) will be issued for all resolutions (for example, via email and/or web-based survey), with a response period from one week to 10 working days, depending on the chair's evaluation of the group consensus on the issue. If no objections are raised on the mailing list by the end of the response period, the resolution will be considered to have consensus as a resolution of the Working Group.

All decisions made by the group should be considered resolved unless and until new information becomes available or unless reopened at the discretion of the Chairs or the Director.

This charter is written in accordance with the W3C Process Document (Section 3.4, Votes) and includes no voting procedures beyond what the Process Document requires.

Patent Policy

This Working Group operates under the W3C Patent Policy (Version of 5 February 2004 updated 1 August 2017). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis. For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.


This Working Group will use the W3C Software and Document license for all its deliverables.

About this Charter

This charter has been created according to section 5.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Charter History

The following table lists details of all changes from the initial charter, per the W3C Process Document (section 5.2.3):

Charter Period Start Date End Date Changes
Initial Charter 02 August 2017 30 June 2019 none
Charter Extension 02 August 2017 31 December 2019 none
Rechartered 27 January 2020 30 June 2020

Rechartering adding one potential new deliverables: Background Fetch.

Charter Extension 17 June 2020 31 December 2020 none
Charter Extension 21 December 2020 31 March 2021 none
Chair updated 05 February 2021 Matt Falkenhagen, Google replaces Jungkee Song, Microsoft
Charter Extension 8 April 2021 30 April 2021 none